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If $$\sin \theta - \cos \theta = \frac{7}{17},$$ then find the value of $$\sin \theta + \cos \theta$$.
Given, $$\sin \theta - \cos \theta = \frac{7}{17}$$
$$=$$> $$\left(\sin\theta-\cos\theta\right)^2=\left(\frac{7}{17}\right)^2$$
$$=$$> $$\sin^2\theta+\cos^2\theta-2\sin\theta\ \cos\theta\ =\frac{49}{289}$$
$$=$$> $$1-2\sin\theta\ \cos\theta\ =\frac{49}{289}$$
$$=$$> $$2\sin\theta\ \cos\theta\ =1-\frac{49}{289}$$
$$=$$> $$2\sin\theta\ \cos\theta\ =\frac{240}{289}$$
$$=$$> $$1+2\sin\theta\ \cos\theta\ =1+\frac{240}{289}$$
$$=$$> $$\sin^2\theta+\cos^2\theta+2\sin\theta\ \cos\theta\ =\frac{529}{289}$$
$$=$$> $$\left(\sin\theta+\cos\theta\right)^2=\left(\frac{23}{17}\right)^2$$
$$=$$> $$\sin\theta+\cos\theta=\frac{23}{17}$$
Hence, the correct answer is Option B
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